Plunger for glass-blowing machines.



No. 805,335. PATENTED NOV. 21, 1905.

- H. BARD. I

PLUNGER FOE GLASS BLOWING MACHINES.

urmoumn FILED APR. '1. 190a.

UNITED STATES PATENT OFFICE.

HARRY BARD, OF MILLVILLE, NEW JERSEY, ASSIGNOR TO MILLVILLE MACHINECOMPANY, OF MILLVILLE, NEW JERSEY, A CORPORATION OF NEW JERSEY.

Specification of Letters Patent.

Patented Nov. 21, 1905.

Application filed April 7, 1903- Serial No. 151,477. I

ing of the glass in the blank or press molds in the manufacture ofbottles having necks of contracted area. My invention is fully shown inthe accompanying drawings, in Which Figure 1 is a view of a blank orpress mold with the plunger within the mass of glass charged into thesame. Fig. 2 is a full-sized View of the plunger and its connected partsin section. Fig. 3 is a sectional plan view on the line a a, Fig. 2; andFig. 4 is a perspective view of the separable part of the plunger.

In the blowing of hollow glassware by ma chinery it is necessary, ofcourse, to insert a plunger in the mass of glass within the pressmoldfor the purpose of forming the neck and head of the bottle and thepreliminary recess to receive the air to finish the article. WVhenmaking bottles or other hollow ware having contracted openings, it isnecessary to provide a straight plunger, as such plunger finishes theinternal wall of the neck and head. In using a straight plunger,however, great difiiculty is experienced in withdrawing such plungerfrom the mass of glass after it has been entered into the same; and theobject of my invention is to overcome this difiiculty and insure theready and immediate withdrawal of the plunger after it has effected thepreliminary recessing of the glass. To prevent the plunger sticking inthe mold, such sticking being due normally to a vacuum between theplunger and the mass of glass, I make the plunger 1 hollow, with anopening 2 extending through the same and communicating near the upperpart of the plunger to the atmosphere through an opening 3. In the lowerpart of this opening or recess 2 a movable member 4: is carried, whichmember is grooved at 5 and is provided with an enlarged opening 6,through which passes a pin 7, securing it to the plunger. Thisarrangement provides for a-certain amount of movement between saidplunger and the movable piece.

This movable piece has an enlarged head 8, shaped like the head of anordinary screw, and this fits the beveled portion 9 in the end of theplunger. I/Vhen the plunger is inserted in the glass, the movable pieceis pressed up into the tubular portion of the plunger and stays thereuntil the plunger is started out of the glass. At this time theslightest movement of the plunger, which might even cause movement ofthe glass, is suflicient to separate.the plunger from the movable piece,which necessarily remains in its lower position due to the force ofgravity, and this slight separation between the parts is sufficient toadmit air from the atmosphere which passes through the tubular portionof the plunger, thereby breaking the vacuum created by the plunger whenit is inserted in the glass, and the plunger may be then removedwithoutdifficulty. The movable piece is not necessarily of the shapeshown, but must be so shaped and arranged as to provide for the passageof air around the same and must have a head exactly fitting the plungerwhen the two are brought together as they are forced into the glass.Instead of having simply a tapered head the upper portion of the movablepiece may also be tapered, and in some instances such piece may betapered from end to end.

Having thus described my invention, I claim and desire to secure byLetters Patent The combination ofa hollow,elongated plun ger for-usewith glass-blowing machines, having an upper opening communicating withthe atmosphere and a lower opening with a flared or beveled mouth, ashort movable plug fit- .ting the hollow bore of the plunger at itslower end, said plug being grooved for the passage of air, a headcarried by said plug and shaped to fit the flaring mouth of the plungerand serving to fully close the lower opening, and a pin carried by theplunger and confining the plug to the same, said plug being slotted toreceive the pin and provide for slight movement with respect to theplunger.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

' HARRY BARD.

Witnesses:

WM. A. LOGUE, B. F. HIREs.

